[Semper Fidelis]

Long time,

Happy to be back online !

Whish to be back in November too

Sincerly

Semper Fidelis

[Bob Kuczewski]

Whish to be back in November too

It's good to have you back now ... and in November!!!

[JoeF]

What small diameter rods might be used in some UPHGs?

Nitinol rods might have won over CF whiskers or rods in the paraglider world. Compare them.

ChatGPT said:
Excellent insight. In the world of paragliders and soft wings, both Nitinol rods and carbon fiber (CF) rods or whiskers have been explored as structural elements in wing profiles, especially for leading-edge support and internal shaping. Here's a clear comparison of the two in this context:
Nitinol Rods (Nickel-Titanium Alloy)
Key Traits:
Shape memory alloy that can flex, bend, and return to its original shape.
Superelastic—can endure significant deformation without permanent bend.

In Paragliders:
Used in place of nylon or carbon rods to shape the leading edge.
Enables tight folding or rolling of the wing without removing rods.
Returns to perfect curvature after unpacking or impact.
Favored in hike-and-fly, backcountry, or travel-focused wings.
Low maintenance and extremely durable.
Resists cracking, splintering, or fatigue failures.
Adds some weight over nylon or CF but often worth the trade-off.
Integrated into wing design via sewn sleeves or channels.
Becoming increasingly popular in modern gliders (e.g., Ozone, Dudek).

Advantages:
Flexible packing.
Long service life.
Survives rough handling.
No need to remove rods before packing.

Trade-offs:
More expensive per unit length than CF.
Slightly heavier than CF for equal volume.
=====================================================================
Carbon Fiber Rods or Whiskers
Key Traits:
Extremely lightweight and stiff composite material.
Rigid; excellent for preserving airfoil shape under load.

In Paragliders:
Previously popular for maintaining precise wing profiles.
Common in performance-oriented wings.
Typically removable to avoid damage during packing.
Fragile under bending—can splinter or crack if folded.
Very light, which benefits glide ratio and acceleration.

Advantages:
High stiffness-to-weight ratio.
Great shape fidelity under tension.
Common and relatively affordable.

Trade-offs:
Must be handled carefully—susceptible to cracking, delamination.
Cannot be folded—requires careful packing or rod removal.
Not ideal for hike-and-fly or travel wings.
Failure often sudden and complete.

Summary
Nitinol wins for resilience, flexibility, and travel convenience—ideal for modern soft wings.
Carbon fiber is still strong for rigid structure and precision shaping, but loses favor in foldable, mobile glider designs.
===================================
Consider studying page on Nitinol wire: https://www.samaterials.com/nitinol/401-nitinol-wires-rods.html

[JoeF]

Removable Child Tube Plug Design Summary

Function:
The plug at the insertion end of the Child Tube is removable to enable compact pack nesting of the spar sections.

Shape and Interface:
The plug is carefully shaped (e.g., with rounded, smooth edges and possibly slight tapering) to:

Soften contact with the Joe-Sock coupler’s Dyneema strapping or fabric socking.

Prevent sharp carbon fiber edges of the Child tube from cutting, abrading, or damaging the strapping or socking under tension and repeated use.

Material & Fit:
The plug is a press-fit insert, sized for a secure but removable fit inside the Child tube’s ID, balancing retention with ease of removal.

Pull-Out Feature:
A tiny, permanently installed pull pigtail is embedded at the center of the plug’s outer face.

This pigtail allows easy manual extraction of the plug between flight sessions.

Its location minimizes interference with the tube interior and strap geometry.

When compressed during flight, it lies flat inside the tube bore and does not disrupt function.

Benefits

Protects costly Dyneema or socking materials from damage.

Enables quick disassembly and reassembly during transport.

Maintains structural integrity and functional reliability of the spar connection system.

User-friendly with a built-in extraction aid.

[JoeF]

Crossbars and Wings: A Reflection

I see the high jump bar —
Not just a test of height or skill,
But the Crossbar of Jesus’ Love,
Set before me with mercy’s call.

Life’s frustrations rise like crosses—
Bars to fall beneath,
Yet also beams to bear,
Each one a call to courage,
A chance to rise again.

My hang glider frames—
Not mere structures of carbon and cord,
But living crosses lifted by grace,
Wings crafted to carry mercy,
To uplift humanity’s weary soul.

In every fall, a lesson of love;
In every rise, a gift of hope.
Through struggle and surrender,
I build not only flight,
But a pathway to freedom—
A promise that even burdens bear wings.

May this work soar as a prayer,
A tangible mercy given back,
Where crossbars become launching points,
And every trial lifts us closer to the skies.

[dhmartens]

We don't not have time to do better. The spring loaded hiking cane. this is simular start at 3 minutes.
https://youtu.be/Hze5MqhCF4U?si=OHhwzXSyqUFdObEL&t=197

[dhmartens]

Another breakthrough:
Portable and Electriic:
Telescopic leading edge and Atos Wing structure.
https://www.youtube.com/watch?v=GWMkb-enEV4

[JoeF]

The helical spring cane product could too easily cause a loss of an eye of the operator or nearby person: huge risk. The stick breaks and becomes non-functional too easily. Bending behavior needs proofing for such a helical stick. Weight-per-spar-benefit ratio needs to be thoroughly explored. We had an earlier mention of the helical expanding stick. We have time to get hang glider spar designs, I hold. The helical spring sticks might be explored by someone for possible uses in TPHGs.

[JoeF]

HG wings soaking up the sun's energy may well one day be featured on some UPHG (ultra portable hang glider). The gained energy might be used for site uses, charging-batteries for various flight session uses or even powering a powered version of the UPHG. Such avenue of exploration is invited. One may look forward when soaking sun's energy is very integrated in some UPHG.

[JoeF]

Seed site will be linking some to this thread.
http://energykitesystems.net/SeedsOfInvention/